To examine whether the inter-channel information supplements intra-channel recovery in image warping. We conduct a preliminary experiment using image super-resolution as an example application. We upsample test images by bilinear and bicubic interpolation, and then refine the upsampled image values by sequential HQLI demosaicking. In particular, we first apply the GRBG CFA pattern to filter the upsampled color image, and estimate the filtered-out color values by the remaining color values. Subsequently, we apply the RGGB CFA to the demosaicked full RGB image, and perform the second-round demosaicking. We then change the CFA pattern to BGGR, and repeat HQLI demosaicking for the final round. In this way, each color component of a pixel is refined by the intensity values in the local neighbourhood of the other two channels. TableREF  compares the reconstruction accuracy, measured by Peak Signal to Noise Ratio (PSNR), before and after demosaicking (i.e., the cross-channel information) on benchmark datasets Set5 [1]}, Set14 [2]}, BSD100 [3]} and Urban100 [4]}. It can be seen that the inter-channel correlation introduced by demosaicking notably improves the intra-channel interpolation, on all test datasets. Numerically, the improvement is upto \(1.57\)  dB and \(1.09\)  dB for bilinear and bicubic intra-channel interpolation respectively.
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